NUI is an abbreviation for Natural User Interface. An NUI refers to an interface designed to command a computer via a method more intuitive for a human, such as a method using voices, gestures or the like of a user, unlike a Text User Interface (TUI) based on a commanding system via the input of text or a Graphical User Interface (GUI) designed to command a computer by manipulating pictures inside a screen via a touch pad and a mouse.
An NUI device is an input device that is required to implement the above-described NUI. An NUI device may be commonly composed of a microphone configured to recognize voices of a user and an RGB camera and/or a depth camera configured to recognize gestures of a user. Such NUI devices have various specifications based on the types thereof. Commonly, applications designed to photograph all or part of the body of a user and utilize the three-dimensional (3D) NUI thereof chiefly recognize the 3D location of a hand or finger of a user and utilize the recognized 3D location like a cursor for a mouse. More specifically, NUI devices are implemented such that a user moves the location of a cursor on a screen by moving his or her hand up, down, left and right in front of the screen and issues a command by further stretching his or her hand and pressing a button located on the screen. Korean Patent Application Publication No. 10-2012-0070133 (published on Jun. 29, 2012) also discloses such a technology.
However, these methods have the following problems. The location of a hand does not consist with the location of a cursor on a screen from a user's viewpoint, and the user naturally views the screen so as to perform interaction based on the cursor on the screen, with the result that the user cannot view his or her hand. Accordingly, the user unnaturally moves his or her hand so as to move the cursor within the screen, and thus a longer time and a more effort are required to perform input at a level identical to that of input via a mouse.
Meanwhile, the above-described background technology corresponds to technical information that has been possessed by the present inventor in order to contrive the present invention or that has been acquired in the process of contriving the present invention, and cannot be necessarily viewed as a well-known technology that had been known to the public before the filing of the present invention.